[Effect of bulbus length of reduction of squint angle after suture fixation].

The principle of the posterior fixation suture popularized by Cüppers in 1971 is to decrease the length of the lever arm. The latter depends on the radius of the globe. For geometric reasons the axial length should have an influence on the surgical effect. There are contradictory results on this problem. Therefore, we conducted a study including 112 patients mainly with non-accommodative convergence excess (average age: 7.0 years, average axial length: 21.7 mm). We measured the axial length of both eyes before performing a retroequatorial myopexy. The amount of symmetrical surgery done in both eyes averaged between 12.0 and 14.0 mm, measuring 5.5 mm behind the limbus, i.e., from the insertion of the medial rectus. Fifty of the 112 patients received additional recession or resection of the medial rectus in one or both eyes. A statistically highly significant negative correlation was found between the axial length and the response to strabismus surgery (surgical effect = reduction of near and distance deviation). The correlation coefficient ranged between -0.29 (for all 112 patients) and -0.69 (for the uniform group of 24 patients with 13 mm surgery) with P < 0.0001. The same correlation was evident between the point of the posterior fixation suture behind the equator (angle of "retroequatoriality" in degrees) and the response to strabismus surgery. It is well known fact that larger deviation show a greater response to posterior fixation sutures.(ABSTRACT TRUNCATED AT 250 WORDS)